It's located at Tarrey Town which you will have to make by doing a side quest in Hento Village (if I spelled that right) It's a abandoned house which you would need to talk to these people who are working on the house. They want to have 20 pieces of wood and you need 3,000 rupees to buy this house and you would do a bunch of stuff and you'll get this store. The side quest is next to Firly Pond.